(no subject)

I am working on vertical chute problem of granular particles. I need the per atom information of energy of particles. When I used dump command, it doesn’t calculate the per atom info and shows error. How can I get the per atom energy info using lammps.
Thank you.
Vikas.

vikas,

it would help a lot, if your e-mail had a meaningful subject line.

I am working on vertical chute problem of granular particles. I need the per
atom information of energy of particles. When I used dump command, it
doesn't calculate the per atom info and shows error. How can I get the per
atom energy info using lammps.

this has only been discussed on this mailing
list a few hundred times. set up a per atom compute
(*which* energy, btw?) and then output that
compute in your dump.

if you need more specific help with this, you
have to provide more specific information about
errors and what you do/did. it is impossible to
give specific help on "it doesn't work".

sorry,
   axel.

I need to compute kinetic energy. In my system, atoms are of only 1 type. There are 1000 atoms in the system and I need to get the kinetic energy value info for each atom. How do I setup a per atom compute because the command asks for the id of the atoms and I have only one type of atoms…

I need to compute kinetic energy. In my system, atoms are of only 1 type.
There are 1000 atoms in the system and I need to get the kinetic energy
value info for each atom. How do I setup a per atom compute because the
command asks for the id of the atoms and I have only one type of atoms..

the documentation for the ke/atom compute is here

http://lammps.sandia.gov/doc/compute_ke_atom.html

i don't see any need to input atom ids anywhere.

axel.

Thanks…and what about rotational energy …is there any command like erotate/sphere/atom…

Thanks..and what about rotational energy .....is there any command like
erotate/sphere/atom...

if it is not in the documentation, it is not there.
if you want it, you need to program it.
should be straightforward, if you use ke/atom
and erotate/sphere as a template.

this is how new features get added to LAMMPS.
btw: have you looked at LIGGGHTS? it support
for granular media simulations is much better
than what LAMMPS has to offer.

axel.

I have done most of the simulation in lammps. I can’t switch to LIGGGHTS. By the way, I think the command ke/atom calculates total ke and then divide it to total no. of atoms. What I need is a file like this:
atom id ke
1 100
2 102
.
.
.
1000 105

means I need ke of each atom separately. Is that possbile???

I have done most of the simulation in lammps. I can't switch to LIGGGHTS. By

LIGGGHTS is based on LAMMPS. there is not much of a switch.

the way, I think the command ke/atom calculates total ke and then divide it
to total no. of atoms.

no it doesn't.

What I need is a file like this:

atom id ke
1 100
2 102
.
.
.
1000 105

means I need ke of each atom separately. Is that possbile???

yes. rather than making unsubstantiated claims,
have a look at the sources and prove it.

as i said before, you can have your information
written to a custom dump file. it will not have exactly
that format but close enough.

axel.

I just did the simulation and I got the desired result for ke. Can you suggest me to how to get the reusult in this format for other rotational energy as well.

Sorry I was not doing any claim, I was merely asking…

I just did the simulation and I got the desired result for ke. Can you
suggest me to how to get the reusult in this format for other rotational
energy as well.

grab a text editor and write your own compute?

axel.

Sorry I was not doing any claim, I was merely asking..

you wrote:

By the way, I think the command ke/atom calculates total ke and then divide it to total no. of atoms

that is a claim and not a question in my book.

axel.

There is now - I just posted an 8 Aug patch for it.

Please try it out,
Steve